I made a video demonstrating one of my favorite nibs: the "Blade Turk" custom grind by Mark Bacas from nibgrinder.com

The nib is sort of a super-ultra-fine architect grind, which means the downstrokes are thin and the cross strokes are wide... but not very wide, being so fine.

Here's a gallery of images showing the pen, the nib, and some art I made with it.

The shape is curved a bit, so the line variation changes based on the angle as you use the pen.It's amazing. The nib is on a TWSBI 580alr which is like the 580al except with some trim differences and a ribbed grip section.

It's a great pen, great nib, and I definitely recommend Mark Bacas's nib services for modifications or repair. I will definitely go through him again for more custom pen work...